Superheater



l. PRIMROSE.

SUPERHEATER.

APPLICATION FILI-:D MAYIo, I9I7.

1,359,916. PatenaNov. 23,1920.

3 SHEETS-SHEET I.

3 nvm/woz I. PRIMROSE.

SUPERHEATER. APPLICATION FILED MAY I0, 1917. 1,359,916, Patented Nov. 23, 1920.

I 3 SHEETS-SHEET 2.

Jig. 2.

J. PRIMROSE.

SUPERHEATER.

APPLICATION FILED MAY lo. 1917.

1,359,91 6 Patented Nov. 23, 1920.

3 SHEETS-SHEET 3- UNITED STATES PATENT OFFICE.'

JOHN PRIMROSE, OF NEW YORK, N. Y., ASSIGNOR TO POWER SPECIALTY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK;

SUPERHEATER.

Specification of Letters Patent.

Patented Nov. 23, 1920.

Application led May 10, 1917. Serial No. 167,624.

T0 all whom it may concern Be it known that I, JOHN PRrMRosE, a subject of the King of Great Britain, residing at New York, in the county and State of New York, have invented certain new and useful Improvements in Superheaters, of which the'following is a full, clear, and eX- act description.

The object of this application is. an improvement in superheaters for steam boilers, the nature of which may be most readily comprehended by the following consideration of the conditions which exist in regardv rings, which may be separate or cast in sec-v tions each of which has several corrugations, greater radial dimensions, so that the surface which they present to the hot gases is increased to several times that of the tubes which they surround. But while in this. respect there is an actual gain in the area of the heat absorbing surface, there is a loss due to the fact that under ordinary conditions such as have heretofore existed in boilers, the increased depth of the flanges or corrugations serves to direct the flow of the gases from the lower portions of the heating surface, protecting` these, as it were, from the wiping effect of the hot flow.

To remedy this, therefore, I use with these superheaters or any others of like characteristics a system of batlling which requires the hot gases to flow over the Asurface of the superheater in a direction substantially at ri ht angles to the axis of the tube sections, w ereby the gases will be caused to wipe thoroughly over the entire exposed surface and between the corrugations..

In the case of superheaters generally it is further necessary, in order to insure the hot gases reaching all parts of the superheater tubes, that the dimensions or area. of the passage of the gases through the space occupied by the superheater be so proportioned that the passing gases will spread out over the entire surface of the superheater. This point is of special importance because it is now known that the rate of absorption by the heating surface increases directly as the weight of hot gases passing per square foot of area through which the heating surface is increased, this being true of all forms of superheaters.

A further improvement which I have introduced is rendered possible'by the character and conditions of the main invention` and this resides in a counter current scheme or, in other words, the steam subjected to the superheater action is caused to travel in a directionvcounter to the flow of the hot gases, the steam of lowertemperature, or the saturated steam from the boiler, entering the superheater where the gases of lowest temperature leave it, while the steam outlet is where these gases are the hottest..

These improvements, as far as it is practicable to do so, are illustrated in the accompanying drawings. In these Figure 1 is a sectional view of a standard type of Babcock & VVilcoX boiler with my improvements applied thereto.

Fig. 2 is a similar view of a Sterling boiler equipped with my improvements, and

Fig. 3 lis a similar view-of a Babcock & IVilcox horizontal cross drum type of boiler with the same improvements.

The several boilers shown are well known in the art and require no detailed eXplana-.

tion or description. In Fig. 1 the super heater A here shown as of the conventional Foster type is supported above the bank of boiler tubes B which are provided with vertical baflies C that cause the gases of combustion to pass through the front half vertically and then through the rear half in in the drawings.

designed and arranged in the usual Way. A baille E lies back of the first bank l" and the hot gases after passing over these tubes flow over the top of the batlie onto the superheater A and over to the second bank at substantially right angles to the tubes. The headers (i in this case are practically contiguous and together with the baffle shelf H form a substantially complete horizontal battle below the superheater.

A similar arrangement is shown in Fig. 3 in which a central baille D through the superheater causes the hot gases to pass over the latter at substantially right angles to its axis, as indicated by the arrows.

As above stated, the form or character of the .superheater is largely immaterial, but the number, length and dimensions of its tubes should be so determined that that area of the gas passage through or over it be such as to force the gases to spread out over all of it, and at a rate of travel that will insure good transfer of heat from the gases to the heating surface. For example, to secure the best results it has been determined that 2000 lbs. of hot gas should pass over each square foot of superheater per hour, and the area of-the passage Way between the superheater elements should therefore be adjusted or proportioned according to the draft to secure the passage over the superheater of this amount of gas.

The counter current plan is also illustrated For example in Fig. 2 the saturated steam from the boiler drum is led by the pine K to the header. L which is on the side of the cooler gases, and the outlet for the steam is from the header M which is immediately below that element which is exposed to the hottest gases coming from the re box. v

- The above described construction and arrangement are of great and growing importance in this art7 because the tendency of present day practice is to reduire higher degrees of super heat` and unless the heating surface of the superheater be effectively placed in the boiler it is impossible to get enough heating surface to accomplish the desired result.

W hat I claim is:

l. The combination with a steam boiler of a superheater having tubes with circumferential corrugations, of a system of battles placed with reference to the superheater tubes and adapted thereby to cause the hot gases to flow over the heating surface of the tubes in a direction at right angles to the axis of the same so as to pass directly over gud in contact with the entire heating surace.

2. The combination with a steam boiler of a superheater having tubes enveloped in metal rings independently constructed and affixed to the tubes so as to form a corrugated exterior heating surface and batlie plates placed With reference to the super heater tubes and adapted thereby to cause the hot gases to flow over the corrugated heating surface at right angles to the axis of the tubes so as to pass directly over and in contact With the entire heating surface.

In testimony whereof I aiiix'my signature.

JOHN PRIMROSE. 

